Apparatus and method for operating an emission abatement system

ABSTRACT

A method of operating an emission abatement system includes advancing a liquid agent to an atomizing nozzle and advancing pressurized air to the atomizing nozzle. The method further includes impinging the pressurized air on the liquid agent at a tip of the atomizing nozzle to shear liquid agent particles from the liquid agent. The method further includes advancing the liquid agent particles through the atomizing nozzle to an emission abatement device. An emission abatement system and atomizer apparatus are also disclosed herein.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to atomizers, and specifically,to atomizing nozzles used with liquid agents in emission abatementsystems.

BACKGROUND

Atomizers are typically used in an emission abatement system foratomizing a liquid agent to be used for abating emissions such as thosepresent in exhaust gases produced through operation of an internalcombustion engine. For example, hydrocarbon fuel may be atomized for usein an exothermic reaction for regenerating a soot particulate filterthat traps soot present in the exhaust gases of an engine. Urea may beatomized and used as a reductant in selective catalytic reductioncatalysts, which reduce the oxides of nitrogen typically present in theengine exhaust. Pressurized air can be mixed with a particular liquidagent at a location upstream of the an atomizing nozzle used toultimately deliver an atomized spray for use in an emission abatementsystem.

SUMMARY

According to one aspect of the disclosure, a method of operating anemission abatement system may comprise advancing a liquid agent to anatomizing nozzle and advancing pressurized air to the atomizing nozzle.The method may further include impinging the pressurized air on theliquid agent at a tip of the atomizing nozzle to shear liquid agentparticles from the liquid agent. The method may further includeadvancing the liquid agent particles through the atomizing nozzle to anemission abatement device.

According to another aspect of the disclosure, an emission abatementsystem may include an atomizing nozzle. The system may further include asupply of liquid being deliverable to the nozzle through a liquid agentline. The system may further include a supply of pressurized air beingdeliverable to the atomizing nozzle to impinge on the liquid agent at atip of the atomizing nozzle. The system may further include an emissionabatement device disposed downstream of the atomizing nozzle.

According to another aspect of the disclosure, an atomizing apparatusmay include a body being substantially cylindrical in shape, and havingan opening concentric with a circular cross-section and the openingbeing disposed therethrough. The body may further include a number ofair channels disposed radially therethrough and a number of first liquidagent channels disposed therethrough. Each first liquid agent channelmay be in fluid communication with one of the number of air channels.The apparatus may further include a supply of liquid agent in fluidcommunication with each of the number of first liquid agent channels anda supply of pressurized air in fluid communication with each of thenumber of air channels. The apparatus may further include a number ofatomizing nozzles with each nozzle being disposed at an end of one ofthe number of air channels and each nozzle being directed toward theopening in the body.

According to another aspect of the disclosure, an atomizing apparatusmay include a first and second atomizing nozzle, a supply of liquidagent, and a first and second supply of pressurized air. The apparatusmay further include an air line having the first atomizing nozzledisposed at an end thereof and being in fluid communication with thefirst supply of pressurized air. The apparatus may further include aliquid agent line disposed within the air line. The liquid agent linemay have the second atomizing nozzle disposed at an end thereof andbeing in fluid communication with the supply of liquid agent and thesecond supply of pressurized air.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description particularly refers to the accompanying figuresin which:

FIG. 1 is a diagrammatic view of an exemplary exhaust system;

FIG. 2 is a diagrammatic cross-sectional view of an exemplary atomizingapparatus;

FIG. 3 is a diagrammatic end view of another exemplary atomizingapparatus;

FIG. 4 is a diagrammatic cross-sectional side view of the exemplaryatomizing apparatus of FIG. 3; and

FIG. 5 is a diagrammatic enlarged view of a portion of the exemplaryatomizing apparatus of FIG. 3.

DETAILED DESCRIPTION OF THE DRAWINGS

As will herein be described in more detail, FIG. 1 shows a diagrammaticview of an exemplary exhaust system 10. The exhaust system 10 includesan exhaust pipe 12 through which exhaust gases may flow from a sourcesuch as an internal combustion engine (not shown). The arrows shown inFIG. 1 provide an exemplary representation of the flow direction ofvarious gases and/or fluids that may be present in the exhaust system10.

An atomizer 14 and an emission abatement device 16 are disposed in theexhaust pipe 12 with the atomizer 14 being located upstream of theemission abatement device 16. The atomizer 14 may receive a mixture of aliquid agent and air to produce an atomized spray to be subsequentlyused for emissions abatement. In this exemplary embodiment, the atomizer14 receives a liquid agent from a liquid agent supply 18 through aliquid agent line 20 and pressurized air from an air supply 22 throughan air line 24. An optional air supply 19 may be implemented to mix airwith the liquid agent prior to being advanced to the atomizer 14 througha liquid agent line 20.

In this exemplary embodiment, pressurized air from the air supply 22 mayimpinge the liquid agent (or agent/air mixture) just prior to beinginjected from the atomizer 14 into the exhaust pipe 12, which causes theliquid agent to be sheared into smaller particles than would be createdthrough impingement occurring at a point further upstream of the liquidagent line 20 as is conventionally done. Once the atomized liquid agentis injected into the exhaust pipe 12, it may be used for emissionsabatement.

In this exemplary embodiment, the emission abatement device 16 mayinclude an oxidation catalyst 26 and a filter 28. In one exemplaryembodiment the filter 28 may be a soot particulate filter. Hydrocarbonfuel may be used as the liquid agent which is atomized and aided inadvancement by the flow of exhaust gases downstream to the oxidationcatalyst 26. The catalyst 26 will catalyze an exothermic reactionbetween oxygen present in the exhaust gases and atomized air with theinjected fuel. The catalyst 26 includes catalytic material disposed on asubstrate. The catalytic material may be a precious metal, such asplatinum or palladium, for example. The highly exothermic reactionproduces heat that is transferred to the downstream-positionedparticulate filter 28.

The particulate filter 28 of the emission abatement device 16 may beconfigured to trap soot particles present in the exhaust gases. Fromtime-to-time, the filter 28 needs to be regenerated when becoming fullof soot. The heat generated through the exothermic reaction may be usedto raise the temperature of the soot particles trapped in the filter 28to a temperature sufficient to ignite the particles thereby regeneratingthe particulate filter 28. It should be appreciated that the particulatefilter 28 may be coated with catalytic material thereby eliminating theneed for the oxidation catalyst 26.

In an alternative exemplary embodiment, the emissions abatement device16 may include a selective catalytic reduction catalyst, which reducesthe oxides of nitrogen present in exhaust gases. Urea may be used as theliquid agent in supply 18 to reduce the oxides of nitrogen atappropriate times.

FIG. 2 shows a diagrammatic cross-section of an atomizer 14configuration that may be used in the exhaust system 10. In thisexemplary embodiment, the liquid agent line 20 is disposed within theair line 24 such that the pressurized air in the air line 24 is advancedaround the agent line 20. The agent line 20 includes a channel 28through which a liquid agent (or an agent/air mixture) is advanced. Atan end 31 of the fuel line 20 is a dispersion chamber 30 and anatomizing nozzle 32. The dispersion chamber 30 allows the agent to bedispersed into a larger area than that of the channel 28. Once the agentreaches the dispersion chamber 30, the agent may be initially atomizedwith the atomizing nozzle 32, which injects the atomized agent into anarea 36 located at the nozzle tip 37 of an atomizing nozzle 34. At thenozzle tip 37, the atomized agent is impinged on by the pressurized airtraveling through the channel 26 of the air line 24. The impingement bythe pressurized air causes a “film stripping” effect, which shearssmaller particles of agent from the particles created through the use ofatomizing nozzle 32. The pressurized air also forces the agent throughthe atomizing nozzle 34, which, due to the film stripping, providessmaller atomized particles than those created through conventionalatomization. It should be appreciated that while the atomizer 14 shownin FIG. 1 is configured to deliver an axial atomized spray with respectto the longitudinal axis of the exhaust pipe 12, an atomizer 14 may beconfigured to deliver liquid agent radially outwardly with respect tothe air line 24.

FIG. 3 shows a diagrammatic end view of another exemplary atomizer 14that may be used with the exhaust system 10. In this exemplaryembodiment, the body 38 is cylindrically-shaped, which can be formed tofit within various exhaust pipes 12 having substantially circularcross-sections. The body 38 includes an opening 40 concentricallydisposed therein, which allows exhaust gases to pass therethrough whentraveling downstream in the exhaust pipe 12.

The body 38 includes a number of air channels 42 radially disposedtherein. The air channels 42 extend through the body 38 allowing theopening 40 to be in fluid communication with the area surrounding theouter surface 43 of the body 38. An atomizing nozzle 44 is disposed atan end 46 of each air channel 42 proximate to the opening 40.

FIG. 4 shows a cross-sectional side view of the atomizer 14. In thisexemplary embodiment, the body 38 is shown to include a number of liquidchannels 48, 49 which are disposed within the body 15 such that theliquid channels are substantially parallel with the longitudinal axis ofthe body 15. Each liquid channel 48, 49 is in fluid communication withone of the air channels 42 and the area surrounding ends 50, 52 of thebody 38.

The configuration shown in FIGS. 3 and 4 of the atomizer 14 allows theliquid agent to be supplied through the liquid channels 48 andpressurized air to be supplied through the air channels 42 throughliquid agent line 20 and air line 24, respectively, in a manner similarto that shown in FIG. 1. FIG. 5 shows an enlarged view of the manner inwhich the air and liquid agent interact at each liquid channel 48,49/air channel 42 intersection. Pressurized air is supplied to the airchannel 42 and advanced toward the opening 40. A liquid agent isadvanced from a liquid agent supply 18 into liquid channel 48, 49through each end 50, 52 as illustrated in FIG. 5. Fuel advancing throughthe liquid channels 48, 49 reaches the air channel 42. The pressurizedair flowing through the air channel 42 impinges on the liquid agent thathas advanced into the air channel 42 providing enough force to shearparticles from the liquid agent entering the air channel 42. The liquidagent particles are further advanced through the air channel 42 from themovement of the pressurized air such that that liquid agent particlesreach the respective atomizing nozzle 44, where the particles areatomized and sprayed into opening 40 as illustrated through the arrowsshown in FIGS. 3 and 4.

When the atomizer 14 is disposed in the exhaust pipe 12, exhaust gasesflow through the opening 40 thereby carrying the atomized liquid agentdownstream to other portions of an exhaust system 10, such as anemission abatement device 16. The shearing of the liquid agent with thepressurized air at a position proximate to the atomizing nozzles 44allows smaller particles to be to be advanced through the atomizingnozzle 44. It should be appreciated that the atomizer 14 shown in FIGS.3-5 may be configured such that only a single liquid channel 48 or 49 isused and disposed through an end 50, 52 of the body 38 for delivering aliquid agent to an air channel 42.

It should be further appreciated that the atomizer 14 can be dimensionedto meet particular configurations. For example, the cylindrically-shapedatomizer shown in FIGS. 3 and 4 can be dimensioned to fit various-sizedexhaust pipes. This allows an exhaust pipe 12 to include portions havingdifferent diameters. This allows a portion of the exhaust pipe 12 havinga first diameter positioned upstream of another portion having a seconddiameter with the second diameter being greater than the first. Thisconfiguration permits the atomizer 14 to be dimensioned to fit withinthe portion having the second diameter, which allows the atomizer 14 toinclude an opening 40 large enough to reduce the amount of atomizedair/fuel mixture injected injected across the opening 40 onto a portionof the inner surface of the body 38. Furthermore, having the expandedpipe downstream allows the exhaust gases flowing therethrough to expandbefore reaching the atomizer 14. It should also be further appreciatedthat a similar configuration can be done for the atomizer 14 shown inFIG. 2.

There are a plurality of advantages of the present disclosure arisingfrom the various features of the apparatus, systems, and methodsdescribed herein. It will be noted that alternative embodiments of theapparatus, systems, and methods of the present disclosure may notinclude all of the features described yet still benefit from at leastsome of the advantages of such features. Those of ordinary skill in theart may readily devise their own implementations of apparatus, systems,and methods that incorporate one or more of the features of the presentdisclosure and fall within the spirit and scope of the presentdisclosure.

1. A method of operating an emission abatement system comprising:advancing a liquid agent to an atomizing nozzle, advancing pressurizedair to the atomizing nozzle, impinging the pressurized air on the liquidagent at a tip of the atomizing nozzle to shear liquid agent particlesfrom the liquid agent, and advancing the liquid agent particles throughthe atomizing nozzle to an emission abatement device.
 2. The method ofclaim 1, wherein: advancing the liquid agent comprises advancing theliquid agent through a liquid agent line to the atomizing nozzle, andadvancing pressurized air further comprises advancing the pressurizedair through an air line disposed about the liquid agent line.
 3. Themethod of claim 2, further comprising advancing the liquid agent througha second atomizing nozzle disposed at an end of the liquid agent line.4. The method of claim 1, wherein: advancing the liquid agent comprisesadvancing the liquid agent to the nozzle through a first liquid agentline, and advancing the pressurized air comprises advancing thepressurized air through an air line.
 5. The method of claim 4, whereinadvancing the liquid agent further comprises advancing the liquid agentto the atomizing nozzle through a portion of the air line.
 6. The methodof claim 5, wherein supplying the liquid agent further comprisesadvancing the liquid agent to the atomizing nozzle through the firstliquid agent line, a second liquid agent line, and the portion of theair line.
 7. The method of claim 1, wherein: advancing the liquid agentfurther comprises advancing hydrocarbon fuel to an atomizing nozzle,impinging the pressurized air on the liquid agent further comprisesimpinging the pressurized air on the hydrocarbon fuel at the tip of theatomizing nozzle to shear hydrocarbon fuel particles from thehydrocarbon fuel, and advancing the liquid agent particles furthercomprises advancing the hydrocarbon fuel particles through the atomizingnozzle to the emission abatement device.
 8. The method of claim 7,wherein advancing the hydrocarbon fuel particles further comprisesadvancing the hydrocarbon fuel particles through the atomizing nozzle toan oxidation catalyst.
 9. The method of claim 1, wherein: advancing theliquid agent further comprises advancing urea to an atomizing nozzle,impinging the pressurized air on the liquid agent further comprisesimpinging the pressurized air on the urea at the tip of the atomizingnozzle to shear urea particles from the urea, and advancing the liquidagent particles further comprises advancing the urea particles throughthe atomizing nozzle to an emission abatement device.
 10. The method ofclaim 9, wherein advancing the urea particles further comprisesadvancing the urea particles through an atomizing nozzle to a selectivecatalytic reduction catalyst.
 11. An emission abatement systemcomprising: an atomizing nozzle, a supply of liquid agent beingdeliverable to the atomizing nozzle through a liquid agent line, asupply of pressurized air being deliverable to the atomizing nozzle toimpinge on the liquid agent at a tip of the atomizing nozzle, and anemission abatement device disposed downstream of the atomizing nozzle.12. The emission abatement assembly of claim 11, wherein the liquidagent line is disposed within the air line, and an end of the liquidagent line and an end of the air line are disposed at the atomizingnozzle.
 13. The a emission abatement assembly of claim 12, wherein theend of the liquid agent line comprises a second atomizing nozzle. 14.The emission abatement assembly of claim 13, wherein: the end of theliquid agent line further comprises a dispersion chamber, and the liquidagent is dispersed into the second atomizing nozzle.
 15. The emissionabatement assembly of claim 12, wherein the liquid agent is deliverablethrough the liquid agent line to the air line.
 16. The emissionabatement assembly of claim 11, wherein the liquid agent line comprisesa first and second liquid agent line.
 17. The emission abatementassembly of claim 11, wherein: the supply of liquid agent comprises asupply of hydrocarbon fuel, and the emission abatement device comprisesan oxidation catalyst and a particulate filter.
 18. The emissionabatement assembly of claim 11, wherein: the supply of liquid agentcomprises a supply of hydrocarbons, and the emission abatement devicecomprises a NOx adsorber.
 19. The emission abatement assembly of claim11, wherein: the supply of liquid agent comprises a supply of urea, andthe emission abatement device comprises a selective catalytic reductioncatalyst.
 20. The emission abatement assembly of claim 11 furthercomprising an exhaust pipe having a first portion of a first diameterand a second portion of a second diameter, the first portion beingpositioned downstream of the second portion and the second diameterbeing greater than the first diameter, wherein, the atomizing nozzle andthe emission abatement device are positioned within the second portionof the exhaust pipe.
 21. The system of claim 13, further comprising anumber of second liquid channels disposed through the body and being influid communication with one of the number of air channels and with thesupply of liquid agent.
 22. An atomizing apparatus comprising: a bodyhaving being substantially cylindrical in shape, the body having aopening concentric with a circular cross-section and being disposedtherethrough, a number of air channels disposed radially therethrough,and a number of first liquid channels disposed therethrough, each firstliquid channel being in fluid communication with one of the number ofair channels, a supply of liquid agent in fluid communication with eachof the number of first liquid channels, a supply of pressurized air influid communication with each of the number of air channels, and anumber of atomizing nozzles, each nozzle disposed at an end of one ofthe number of air channels and each nozzle being directed toward theopening in the body.
 23. An atomizing apparatus comprising: a first andsecond atomizing nozzle, a supply of liquid agent, a first and secondsupply of pressurized air, an air line having the first atomizing nozzledisposed at an end thereof and being in fluid communication with thefirst supply of pressurized air, and a liquid line disposed within theair line, the liquid line having the second atomizing nozzle disposed atan end thereof and being in fluid communication with the supply ofliquid agent and the second supply of pressurized air.